Generally, display devices are required to have a viewing angle as wide as possible so that an image can be seen sharply from any visual angles. In particular, in liquid crystal display devices which are prevalent in these years, because a refractive index of a liquid crystal molecule has dependency on visual angles, various techniques have been developed for widening the viewing angle. Note that (i) the visual angle indicates an angle between a screen of a display device and a direction in which the screen is viewed; and (ii) the viewing angle indicates an angular range in which a certain display quality can be obtained.
Depending on an environment in which a display device is used, however, it may be preferable to have a narrow viewing angle allowing only a user himself to view display contents.
For example, a laptop personal computer, a personal data assistant (PDA), and a mobile phone tend to be used in public places where an unspecified number of people may be present, for example, in a train and in an airplane. In such a use environment, in view of protection of confidentiality and privacy, it is preferable that a display device has a narrower viewing angle in order to prevent surrounding people from peeking at display contents. As described above, it has been increasingly requested that a viewing angle of one display device can be limited within a certain range depending on use conditions and a direction of thus limited viewing angle can be changed. Note that this request is directed to not only liquid crystal display devices but also any other display devices in common.
In order to fulfill such a request, for example, Patent Literature 1 proposes a liquid crystal structure including a liquid crystal pixel arrangement section constituting a liquid crystal plane, a shielding element arrangement section in which shielding elements are provided. In this liquid crystal structure, how an image displayed in the liquid crystal pixel arrangement section is seen can be controlled, for example, by causing the shielding element arrangement section to be in an orderly shielding state. Specifically, as illustrated in FIG. 12, how images are seen is controlled so that only an image B can be seen in a normal line direction of a screen by shielding an image A by use of the shielding elements whereas only the image A can be seen, by shielding the image B by use of the shielding elements, in a visual line in oblique directions that deviate from the normal line direction.